Subject: RE: [mobile-ip] Question about sending BU to CN

From: "Hesham Soliman (EAB)" <[email-masked]>
Date: Sat, 28 Sep 2002 01:05:59 +0200

> Regarding Section 11.6.2, the following para is giving me 
  > some problems :
  > 
  >       "When a mobile node sends a Binding Update to its home agent
  >       to register a new primary care-of address (as described in
  >       Section 11.6.1), the mobile node SHOULD also start a return
  >       routability procedure to each other node for which an 
  > entry exists
  >        in the mobile node's Binding Update List, as 
  > detailed below.  Upon
  >       successful return routability procedure and after receiving a
  >       successful Binding Acknowledgement from the Home 
  > Agent, a Binding
  >       Update message is sent to all other nodes.  Thus, 
  > other relevant
  >       nodes are generally kept updated about the mobile 
  > node's binding and
  >       can send packets directly to the mobile node using 
  > the mobile node's
  >       current care-of address."
  > 
  > Shouldn't the RR be started only after the BA is received 
  > from the HA ?
  > When the
  > MN moved from FN1 (Foreign Network 1) to FN2 and sent the 
  > BU to it's HA, it
  > has
  > entries in it's BUL for CN's it was interracting with while 
  > it was in FN1.
  > So if it sent the
  > BU and started the RR before receiving the BA (or atleast 
  > before BA was
  > sent by
  > the HA), it is possible that the RR packets meant for the 
  > MN at FN2 would
  > get
  > routed to it's COA at FN1. this means that the HoT message may not
  > propagate
  > properly to the MN's new COA.
  > 
  > Is this problem correct ? 

=> The MN doesn't necessarily do RR as a result of movement.
So this might need to be explpained as a special case
(BU lifetime expires at the same time that the MN
moves).

Hesham